Certain water heater appliances include a tank therein. Heating elements, such as gas burners, electric resistance elements, or induction elements, heat water within the tank during operation of such water heater appliances. In particular, the heating elements generally heat water within the tank to a predetermined temperature. The predetermined temperature is generally selected such that heated water within the tank is suitable for showering, washing hands, etc.
During operation, relatively cool water flows into the tank, and the heating elements operate to heat such water to the predetermined temperature. Thus, the volume of heated water available at the predetermined temperature is generally limited to the volume of the tank. According, water heater appliances are sold in various sizes to permit consumers to select a proper tank volume and provide sufficient heated water. However, large water heater appliances with large tanks occupy large amount of space within a residence or business. In certain buildings, space is limited and/or expensive. Thus, utilizing large water heater appliances can be impractical and/or prohibitively expensive despite needing large volumes of heated water.
To provide relatively large volumes of heated water from relatively small tanks, certain water heater appliances utilize a mixing valve. The mixing valve permits water within the water heater's tank to be stored at relatively high temperatures. The mixing valve mixes such high temperature water with relatively cool water in order to bring the temperature of such water down to suitable and/or more usable temperatures. Thus, such water heater appliance can provide relatively large volumes of heated water without requiring large tanks.
To operate efficiently, water heater appliances with mixing valves generally determine whether hot water is in demand or is flowing. When water is flowing through the mixing valve, the mixing valve adjusts the ratio of relatively hot water and relatively cold water in order to control the temperature of water supplied downstream. Certain water heater appliances utilize a flowmeter or a flow sensor to determine a flow rate of water through the mixing valve, but such devices can be unreliable. In particular, flowmeters and flow sensors include moving components that can clog or otherwise malfunction due to hard water or debris.
Accordingly, a water heater appliance having a mixing valve that includes features for determining a flow rate of water through the mixing valve would be useful. In particular, a water heater appliance having a mixing valve that includes features for determining a flow rate of water through the mixing valve without using a flowmeter or a flow sensor would be useful.